Brush-holder.



H. F. T. ERBEN.

BRUSH HOLDER.

APPLICATION IILBD O0T.17,1903.

905,675. Patented Dec. 1, 1908.

Inventor: Hermann FT. Erben. b M, 32%;.

UNITED- STATES PATENT OFFICE.

HERMANN F. T. ERBEN, OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

BRUSH-HOLDER.

Specification of Letters Patent.

Patented Dec. 1, 1908.

Application filed October 1'7, 1903. Serial No. 177,431.

ing at Schenectady,;in the county of Schenectady, State ofNew York, haveinvented certain new and useful Improvements in 'Brush-Holders, ofwhich'the following is a specification.

The object of my present invention is to improve the construction. andoperation of brush-holders of dynamo-electric machines.

One of the particular objects of my invention is to improvebrush-holders in such a manner as to better fit them for use with highspeed machinery, though all of the features' of my invention are notlimited to such use.

My invention consists in certain features of construction andarrangement all of which will be pointed out in the claims annexed toand forming part of this s ecification.

For a better under-stunt ing of my invention, reference may be had tothe accompanying drawings in which I have illustrated one embodiment ofit.

()f the drawings, Figure 1 is an elevation showing the brush-holder anda portion of the commutator with which it coti'peratesa.

Fig. 2 is a plan of the brush-holder; Fig. 3 is a perspective viewillustrating the con struction of the pivot brush-carrying frame; Fig. 4is a perspective view; and Figs. 5 and 6 are elevations showing aslightly modified form of brush-clamping means.

Referring to the drawin s, 1 represents the stationary member of t ebrush-holder. This member which is preferably made of cast metal isadjustably mounted upon a brush-holder carrying stud or member 2 whichisshown as passing through a hole, formed for the purpose in thestationary member 1. A set-screw 3 at the rear end of the member 1 bearsagainst the stud 2 to rigidly secure the m'mber 1 to the stud in anydesired position. The member 1 is formed at one end w th a recess 4 inwhich the spirally coiled end of a spring 5 is located. The inner end ofthespring 5 passes through a slot 6 formed in a bolt 7 which passestransversely through and is journaled in the side walls 4' of the recess4. The head of the bolt 7 has swireled to it a lover or handle 8 by menn; of which the bolt 7 'nnry be rotated to vary and adjust the tensionof the spring 5. Suitable teeth 9 are of the pivot frame to urge thecarried by the member 1 by which 1 8 may be locked in different angularpositlons.

A pin 10,- preferably formed of steel, passes through a hole formed inthe member 1 being located so that it is between the stud 2 and thecommutator when the brush is in its operative position. The ends of thepin 10 project and upon the projecting ends the movable member 11 of thebrush-holder is pivotally mounted. The member 11 of the, brush-holder ispreferably formed out of sheet metal such as sheet steel. It consists ofa pair of portions 12 which may be parallel and which embrace themember 1. These portions are formed with elongated openings 13 throughwhich the stud 2 passes. A connecting portion 14 unites the sideportions 12 to which it is substantially perpendicular. A projectingportion or lip 15 extends substantially perpendicularly from the upperedge of the portion 14. A bolt 16 extends perpendicularly from theportion 14 near its center part preferably being riveted to saidportion. Apertures are formed in the sides 12 in which the ends of pin10 are journaled. Preferably the portions 12, 14 and 15 of the member 11are all parts of a single piece of sheet steel which may be punched orotherwise worked into the form desired.

The brush 23 is clamped a 'ainst the front face of the portion lief t .epivot frame with its upper end abutting against the under surface of theportion 15. As a means for clamping the brush to the pivot frame Iprefer to em lay a spring washer 17 which surrounds th against the frontside of the brush which is apertured to receive the bolt 16. A clampingnut 18 threaded on the end of the bolt 16 is used to force the washeragainst the brush.

In practice I prefer to place a piece of sheet copper 19 or the likebetween the brush and the portion 14 of the frame. A flexible conductoror igtail 20 has one end secured by soldering or in an other suitablemanner to the plate 19. T e'other end of the flexible conductor20 isclamped to the upper side of the member 1 by a clamping screw 21. Thefree end 5 of .the spring 5 which is curved reversely to the curve ofthe spiral portion bears against the ortion 15 rush into contact withthe commutator 22. This arlever e bolt 16 and bears rangement of thespring is an important feature as the bow of the spring gives thenecessary clearance for the screw 21 and the flexible conductor 20. t

I have shown in full lines the position of the pivoted frame when aconsiderable extent of the brush is unconsumed. The position of theframe indicated by the dotted lines in this figure is the one assumedwhen the brush is nearly reduced to its minimum operative. length. Itwill be observed that the parts are so arranged that the position of thebrush upon the commutator does not change materially as the brush isconsumed. It will also be observed that the apertures 13 formed in theside walls of the frame 11 are arranged so that the stud 2 does notinterfere with the normal movements of the piv" oted frame but when thebrush is practically worn away the rear portions of the sides 12 willengage with the stud 2 and thus prevent the frame from engaging thecommutator to the detriment alike of the commutator and frame.

In the construction shown in Figs. 4, 5

and 6 the spring washer 17 is formed with a flanged portion 17' whichbears against the upper end of the brush. A pair of radial ribs orprojections 24; are formed on the outer surface of the washer 17. Theseribs engage in radial grooves 25 formed for the purpose in the inner endof the clamping nut 18. The engagement between the ribs 24 and thegrooves 25 locks the clamping nut to the spring washer and preventsrelative rotation between them, at the same time the flanged portion 17,prevents a rotationof the washer with respect to the brush. I find thisconstruction quite desirable in some cases as owing to the inelasticcharacter of the carbon brush and to the fact that the temperature towhich the brush is raised has a tendency to modify the resiliency of thespring washer there is atendency for the brush to become loose unlessspecial preventive means are adopted.

A brush-holder constructed in accordance with my invention ashereinbefore described is exceedingly compact, simple and efiicient andpossesses many advantageous qualities among which are the following. Thefrictional forces retarding the movements of the movable member of thebrush-holder are reduced to a minimum by the use of the small ivot pin.The movable member of the rush-holder is very light and ithas a smallmoment of inertia which is important, espe' cially for use in high speedmachines. \Vhat I claim as new and desire to secure by Letters Patent ofthe United States. is:

I. In a brush-holder, a fixed member provided with a transverse aperturethrough which a supporting stud may pass, and a movable member pivotedto, said fixed member at a point one side of said aperture and providedwith a portion normallv out of engagement with the stud but adapted toengage the stud to prevent a movement of th movable. member into aposition in which it would engage the commutator.

2. In a brush-holder, a fixed member pro vided with a transverseaperture through which a supporting member may be passed, a movablebrush-carrying frame provided with portions which embrace the fixedmemher, a pivotal connection between the fixed member and thebrush-carrying member at a point at one side of the aperture, andapertures formed in the sides of the embracing members, the walls ofsaid apertures normally clearing the supporting member but-- arranged toengage it to prevent an excessive movement of the frame.

3; In a brush-holder. a fixed member, and a movable brush-carryingmember pivoted to said fixed member, the movable member being formed outof sheet metal and being provided with an integrally formed lip orextension against which the upper end of the ing portion against. whichoneside of the brush rests, and an extension or lip against which theupper end of the brush abuts, and means on said connecting portion forclamping the brush thereto.

5. In a brush-holder, a pivoted frame to which the brush is rigidlysecured, provided with a projection 'or lip against which the upper endof the brush abuts, and a spring having an adjustable spiral portion,and a portion which is reversely curved with respect to the spiralportion bearing-against said projection.

6. In a brush-holder, a fixed member, a movable member pivoted theretoto which the brush is rigidly secured, and a curved,

spring and a pivot by which one end of the spring is supported and aboutwhich a portion of it is coiled in an inverse direction to said curve.the pivot being carried by the fixed member and the other end of thespring being arranged to force the brush against the commutator.

7. In combination, a stationary brushholder member rovided with anaperture, a supporting stuc passilizg through said aperture to which thesai stationary brushholder member is rigidly secured, and a. movablebrush-carrying frame to which the.

brush may be rigidly clamped provided with portions which embrace thestationary member of the brush-holder. theembracing portions beingprovided with apertures through which the supporting stud may pass andbeing pivoted to the stationary member atone side of its stud-receivinaperture the studreceiving apertures of 5m movable member being somewhatlarger than the stud wherebg a limited pivota movement of the mova lemember may take lace.

8. In combination, a rush and a holder therefor, comprisin a stationarymember and a movable mem er pivoted to said stationary member, saidmovable member being formed of a single piece of sheet metal bent intothe form of a U and having the leg portions thereof engaging with saidstationary member, the yoke portion of said movable member beingarranged parallel to vthe length of the brush, and means for clampingthe brush against said yoke portion.

9. In a brush-holder, a stationary member having a recess formed in it,a movable member pivotally connected therewith, and a tension spring,one end of said spring being formed into a spiral said spiral end beinglaced in the recess in the stationary memer and the other end 'of saidspring being arranged to engage the movable member.

10. In a brush-holder, a stationary member having a recess formed in it,a movable member plv'otally connected to the stationary member, flexiblemeans electrically connecting the movable and stationary members, and atension spring having a portion at one end curved spirally and placed inthe recess in the stationary member, the other end of said springengaging the movable member and a portion between said other end andsaid coiled end being curved reversely to the curve of the spiralportion to clear the flexible means connecting the two members.

11. In combination, a brush and supporting means therefor comprising astationary member, a U-shaped brush supporting member formed out ofsheet metalthe ends of which are pivotally connected to said stationarymember, means for securing the brush to said support with one of itssides in engagement with the yoke of said support. said means includinga bolt passing trans versely through the brush and the yoke, and meansfor limiting the pivotal movement of said U-shaped member to flreventengagement between it and the commutator.

12. In combination, a brush and supporting' means therefor comprising astationary member, a U-shaped brush-supporting member formed of asinglepiece of sheet metal and having its legs pivotally connected tothe stationary member and its yoke portion arranged parallel to thelength of the bru h. means on said yoke portion for clamping the brushthereto, and means for limiting the pivotal movement of said U-shapedmember to prevent engagement between it and the commutator.

In witness whereof, I have hereunto set my hand this 16th day ofOctober. 1903.

HERMAXX I T. ERBEX. \Vitnesses HELEN Oaronn, G. C. HOLLISTER.

